1. Field of the Invention
The present invetnion relates to pressure transducers for converting pneumatic or hydraulic pressure changes to electrical signals and more specifically to improved capacitive pressure transducers of the type employing a flexible diaphragm.
2. Description of the Prior Art
Co-pending patent application Ser. No. 330,527 filed in the names of the present inventors concerns a capacitive pressure transducer that includes a housing, diaphragm having a flexible concave surface formed therein, and a rigid plate disposed substantially parallel to the diaphragm such that an air gap is formed between the rigid plate and the diaphragm. In one embodiment of the invention of application Ser. No. 330,527, the rigid plate is formed from a metallic disk containing an annular groove. A layer of mica is interposed between the grooved face of the disk and the diaphragm. When pressure is applied or removed from the diaphragm the concave portion of the diaphragm deflects so as to effectively alter the air gap between the plate and the diaphragm thus changing the capacitance of the unit as a function of the magnitude of the pressure change.
The present invention provides an improvement over the above-described transducer and exhibits increased sensitivity and linearity as well as decreased transient temperature sensitivity.